temp = input('请输入数字\n')
while not temp.isdigit():
    temp = input('请输入整数\n')
year = int(temp)
if year%400 == 0:
    print('是润年')
else :
    if year%4 == 0:
        if year%100 == 0:
            print('不是润年')
        else:
            print('是润年')

        
